Pressure cooker

[william]

Hi all
After about seven weeks of rain and tropical storms we had some nice weather yesterday, decided to make a fire to dry out my oven. I was cleaning out my basement from construction projects and had lots of junk wood to burn, after about four hours had a dome temp of about 900f and hearth was in the 800f range. I knew the oven was damp from the humidity and the driving rain that would enter thru the oven opening but really had no idea since I just finished this build a few months ago. I left the coals spread out over the hearth for about a hour and it was getting dark so I put my new door in and had dinner.
Afterwards I went out to check the oven temp and saw that all around the perimeter were the outer shell meets the slab water was not pouring but being driven out there was quit a bit. I think what was happening was that over the seven weeks of rain, water was entering thru the floor entry bricks and migrating down into the insulation below the oven floor. Because everything is waterproofed on the exterior it was acting like a pan and filling up, when I put that door in the heat created pressure and forced the water out were the outer shell meets the slab. My oven sits on Three inches of insulated vermiculite concrete and two inches of cal sil board, both are like sponges, I think also the were the fiber for the dome meets the floor insulation the water wicked up as I had some steam coming out the small hole I left in the top of the outer dome shell. I remember when I was building that I thought of the entry being a problem for water exposure. I am going to have to make second outer door for my entry to keep the rain from entering thru this vulnerable area. Anyone else out there had this happen.
Bill

[Gulf]

Bill,
I'm glad to say that I have no experience with a wet oven. I took a lot of pains during and since my build to help keep this from happening. I say "help", because there is not much that we can do when mother nature "changes the rules". A driving rain will find a way, even if we are very careful. I'm not sure if you did, but leaving a reveal on the outer arch makes a great socket to place an outer door. My outer door is made from treated wood. I only set it in place when the insulted door is secured in place. It never sees any real heat from the oven. But, so far it has helped on at least a couple of occasions against driving rains. At the bottom of the door is a "kick down" door stop. It keeps the door in place and secure from wind.

[david s]

Hi Bill,
We live in the tropics too and this happens almost every year to our oven. Waterproofing the outside works fine apart from driving torrential rain that gets in. A roof over the oven is the best remedy, but is costly in materials and time. I have a drain hole in the bottom of my supporting slab which helps accumulated water escape. If you see steam then you are going at it too hard and you risk damage. Keep the fire gentle. We find about two or three long burns restores normal oven function. A hand held to the outer shell tells you a lot. If it's hot then the oven insulation is wet. Also leaving the door off is better so long as it's not raining. Our oven grows mould on the inside if it's wet and the door is in place.

[william]

Hi
Did another long burn today still getting some water from the perimeter, the steam seems to be subsiding from the hole I drilled on the exterior top dome.Your right Dave about the temp of the outer shell can feel a difference from what is was before. As for mold that's a fact of life here.

[Mullins]

Hi Bill,
We live in the tropics too and this happens almost every year to our oven. Waterproofing the outside works fine apart from driving torrential rain that gets in. A roof over the oven is the best remedy, but is costly in materials and time. I have a drain hole in the bottom of my supporting slab which helps accumulated water escape. If you see steam then you are going at it too hard and you risk damage. Keep the fire gentle. We find about two or three long burns restores normal oven function. A hand held to the outer shell tells you a lot. If it's hot then the oven insulation is wet. Also leaving the door off is better so long as it's not raining. Our oven grows mould on the inside if it's wet and the door is in place.

Hi David,

Out of interest, did you build the drain prior to pouring the hearth or incorporate/drill it in afterwards? I am thinking about doing this...

Thanks

Eoin

[david s]

Eoin,
I incorporated it into the casting of the supporting slab. A one inch hole covered with insect mesh to prevent their intrusion.

[william]

Hi
After the second firing the oven is holding heat and appears to be pretty dry, Don't want to have to do this again so I started a exterior door to keep on when I am not using the oven.
I had a piece of surfboard foam in the shop so I cut out a plug see photo and to make it look nice I carved some lauaii ferns in the front, they grow in the rocks around my property.. After I take it home and tweak the fit I will apply fiberglass resin to it and paint a faux bronze finish it. will post a picture when it is done. Thinking about this water issue I think if I had built a full enclosure over the oven it would be really difficult to dry out as I had so much water that escaped around the perimeter, The entry is a very vulnerable spot.
Bill

[Gulf]

Very Nice work!

[UtahBeehiver]

Dakine................

[Gulf]

Dakine................

I know that this going to be cool .

Russell, I know that you have been all over the world. But, could you let a Mississippi "redneck" in on what that means .

[UtahBeehiver]

Gulf, You should know, it is Creole, well Hawaiian Creole that is..........for me basically "cool"

Da kine /də ˈkaɪn/ is an expression in Hawaiian Pidgin (Hawaii Creole English), probably derived from "the kind", that usually functions grammatically as a placeholder name (compare to English "whatsit" and "whatchamacallit"), but can also take the role of a verb, adjective, or adverb

[william]

Hi
Completed the bronze finish on my outer door, I did some water tests with the hose seems reasonably workable, hard place to totally water proof. I read another thread about someone with a similar problem.
I would think with all the rain back east that we might hear more of this. I would recommend anyone building a oven or that has one to make a simple Styrofoam plug could save a few drying fires
Bill

[UtahBeehiver]

I would have never guessed that was an old surfboard. With the finish it looks like an old vintage piece of wood. What island you on, happen to be in Kauai as I write this.

[william]

Hi Utah
That's not an old surfboard., it is made from the foam that they carve boards out of just a denser Styrofoam. I am in Honolulu
Bill

[UtahBeehiver]

I have lots of family in Oahu and on the island of Maui but sadly I am a mainlander. I do like your "storm" idea and going to incorporate one for my Utah build.